The present invention broadly relates to a new and improved construction of a tube gripping system for a winder chuck for winding synthetic filament threads or yarns or the like. In particular, the present invention concerned with generation of gripping forces which act via tube gripping elements, during formation of a thread package, to hold a bobbin tube or thread package forming or formed on a bobbin tube securely on the chuck.
Generally speaking, the chuck for a winding machine as contemplated by the present development comprises a first axially moveable part, a second part spaced axially from the first axially moveable part, an elastically deformable body disposed between the first and second parts to bias them in a direction increasing the spacing between the first and second parts, and with tube gripping elements moveable radially in response to axial movement of the first axially moveable part.
Chucks for winding synthetic filament threads or yarns are known, for example, from U.S. Pat. No. 4,336,912, granted June 29, 1982, U.S. Pat. No. 4,460,133, granted July 17, 1984, U.S. Pat. No. 3,030,039 and U.S. Pat. No. 4,458,850, granted July 10, 1984. These chucks are incorporated in use in a winding machine, being mounted cantilever-fashion for rotation about their own longitudinal axes, as exemplified for example by, U.S. Pat. No. 4,014,476, granted Mar. 29, 1977 and European Pat. No. 73,930, published Nov. 19, 1987. and European Published Patent Application No. 161,385, published Nov. 19, 1987.
During package building or formation, the chuck must rotate around its own longitudinal axis and simultaneously hold the bobbin tube or tube, in which the package is continuously being wound, for slip-free rotation with the chuck. For this purpose, it is known to force tube gripping elements radially outwardly against the internal surface of the bobbin tube by generating an axially directed gripping force; see for example, U.S. Pat. No. 3,052,420, U.S. Pat. No. 3,554,455, U.S. Pat. No. 4,068,806, granted Jan. 17, 1978, U.S. Pat. No. 4,142,690, granted Mar. 6, 1979, U.S. Pat. No. 4,232,835, granted Nov. 11, 1980, and British Pat. No. 2,023,256, published Dec. 28, 1979. As shown in U.S. Pat. No. 4,142,690, the gripping forces are usually generated by groups of Belleville springs.
There has been disclosed a new chuck design in which the tube-carrying part and the bearing part are made in one piece. In this connection reference is made to European Patent Application Ser. No. 86113104.3 published as European published Patent Application No. 0,217,276, published Apr. 8, 1987 and U.S. application Ser. No. 06/911,816, filed Sept. 26, 1986, to the latter of which reference may be readily had and the disclosure of which is incorporated herein by reference.
A tube gripping system has been proposed in which the gripping forces are generated by bodies of porous elastomer. Equivalent applications again have been filed in Europe under European patent application Ser. No. 86113787.5 published as European Published Patent application No. 0,219,752, published Apr. 29 1987 and U.S. application Ser. No. 919,652, filed Oct. 16, 1986, now U.S. Pat No. 4,784,343, granted Nov. 15, 1988, to the latter of which reference likewise may be readily had and the disclosure of which is incorporated herein by reference.
As described in the aforementioned U.S. application Ser. No. 06/919,652, now U.S. Pat. No. 4,784,343, the generation of gripping forces by Belleville springs is associated with several problems. Certain problems of such elements will be subsequently emphasized in the course of describing the drawings of this disclosure. The problems of Belleville springs can be solved by the use of porous elements in accordance with the aforementioned commonly assigned U.S. application Ser. No. 06/919,652, now U.S. Pat. No. 4,784,343, but the suspicion remains that in the longer term, such elastomeric materials will be subject to aging effects which will prejudice the gripping performance. If this occurs in practice, the force-generating elements must be exchanged. Furthermore, the assembly and release forces are very high.